Electric arc welding is a complex electrical phenomenon having many process control variables affecting the quality of the weld, whether using spray transfer, pulse transfer, DC GMAW welding or AC welding. In constant voltage welding processes, the welding process is normally controlled by the welding current I.sub.a. When the voltage is held constant, changes in the CTWD cause current changes as well as other process variations; therefore, control arrangements using the volts/ampere characteristics curve for the process have inherent limitations. The contact tip to work distance CTWD has a major influence on current since the current increases as the CTWD decreases and vice versa. Attempts to regulate the DC GMAW welding process based upon electrode stickout or CTWD have presented difficulties, since these parameters are difficult to determine on a real time basis. There is no weld process parameter heretofore measurable that provides a control signal essentially unaffected by arc current. Even more importantly, there has been no parameter to create a control signal to directly regulate on a real time basis the arc length. It is known that maintaining this distance between the bottom of the electrode and the workpiece at a fixed value will result in superior and repeatable weld quality.